Corneal modification via implantation

ABSTRACT

A method for modifying the curvature of a live cornea to correct a patient&#39;s vision. The live cornea is first separated into first and second opposed internal surfaces. Next, a laser beam or a mechanical cutting device can be directed onto one of the first and second internal surfaces, or both, if needed or desired. The laser beam or mechanical cutting device can be then used to incrementally and sequentially ablate or remove a three-dimensional portion of the cornea for making the cornea less curved. An ocular material is then introduced to the cornea to modify the curvature. The ocular material can be either a gel or a solid lens or a combination thereof. In one embodiment, a pocket is formed in the central portion of the cornea to receive an ocular material. In another embodiment, a plurality of internal tunnels are formed in the cornea to receive the ocular material. The ocular material can be either a fluid such as a gel or a solid member. In either case, the ocular material is transparent or translucent, and can have a refractive index substantially the same as the intrastromal tissue of the cornea or a different refractive index from the intrastromal tissue of the cornea.

RELATED APPLICATIONS

This application is related to applicant's application Ser. No.07/844,879, filed Mar. 3, 1992, which is a continuation of applicationSer. No. 07/425,928, filed Oct. 24, 1989, now abandoned, which is acontinuation-in-part of application Ser. No. 07/370,095, filed Jun. 22,1989, now abandoned, which is a continuation of application Ser. No.07/221,011, filed Jul. 18, 1988, now abandoned, which is a continuationof application Ser. No. 06/866,302, filed May 23, 1986, now abandoned,which is a division of application Ser. No. 06/760,080, filed Jul. 29,1985, now abandoned.

FIELD OF THE INVENTION

The invention relates to a method and apparatus for modifying a livecornea via injecting or implanting optical material in the cornea. Inparticular, the live cornea is modified by the steps of separating aninternal area of the live cornea into first and second opposed radiallydirected internal surfaces, introducing transparent optical materialbetween the surfaces and then recombining the first and second internalsurfaces.

BACKGROUND OF THE INVENTION

In an ametropic human eye, the far point, i.e., infinity, is focused onthe retina. Ametropia results when the far point is projected either infront of the retina, i.e., myopia, or in the back of this structure,i.e., hypermetropic or hyperopic state.

In a myopic eye, either the axial length of the eye is longer than in anormal eye, or the refractive power of the cornea and the lens isstronger than in ametropic eyes. In contrast, in hypermetropic eyes theaxial length may be shorter than normal or the refractive power of thecornea and lens is less than in a normal eye. Myopia begins generally atthe age of 5-10 and progresses up to the age of 20-25. High myopiagreater than 6 diopter is seen in 1-2% of the general population. Theincidence of low myopia of 1-3 diopter can be up to 10% of thepopulation.

The incidence of hypermetropic eye is not known. Generally, all eyes arehypermetropic at birth and then gradually the refractive power of theeye increases to normal levels by the age of 15. However, ahypermetropic condition is produced when the crystalline natural lens isremoved because of a cataract.

Correction of myopia is achieved by placing a minus or concave lens infront of the eye, in the form of glasses or contact lenses to decreasethe refractive power of the eye. The hypermetropic eye can be correctedwith a plus or convex set of glasses or contact lenses. Whenhypermetropia is produced because of cataract extraction, i.e., removalof the natural crystalline lens, one can place a plastic lens implant inthe eye, known as an intraocular lens implantation, to replace theremoved natural crystalline lens.

Surgical attempts to correct myopic ametropia dates back to 1953 whenSato tried to flatten the corneal curvature by performing radial cuts inthe periphery of a corneal stroma (Sato, Am. J. Ophthalmol. 36:823,1953). Later, Fyoderov (Ann. Ophthalmol. 11:1185, 1979) modified theprocedure to prevent postoperative complications due to such radialkeratotomy. This procedure is now accepted for correction of low myopiafor up to 4 diopter (See Schachar [eds] Radial Keratotomy LAL, Pub.Denison, Tex., 1980 and Sanders D [ed] Radial Keratotomy, Thorofare,N.J., Slack publication, 1984).

Another method of correcting myopic ametropia is by lathe cutting of afrozen lamellar corneal graft, known as myopic keratomileusis. Thistechnique may be employed when myopia is greater than 6 diopter and notgreater than 18 diopter. The technique involves cutting a partialthickness of the cornea, about 0.26-0.32 mm, with a microkeratome(Barraquer, Ophthalmology Rochester 88:701, 1981). This cut portion ofthe cornea is then placed in a cryolathe and its surface modified. Thisis achieved by cutting into the corneal parenchyma using a computerizedsystem. Prior to the cutting, the corneal specimen is frozen to −18° F.The difficulty in this procedure exists in regard to the exact centeringof the head and tool bit to accomplish the lathing cut. It must berepeatedly checked and the temperature of the head and tool bit must beexactly the same during lathing. For this purpose, carbon dioxide gasplus fluid is used. However, the adiabatic release of gas over thecarbon dioxide liquid may liberate solid carbon dioxide particles,causing blockage of the nozzle and inadequate cooling.

The curvature of the corneal lamella and its increment due to freezingmust also be calculated using a computer and a calculator. If thecorneal lamella is too thin, this results in a small optical zone and asubsequent unsatisfactory correction. If the tissue is thicker than thetool bit, it will not meet at the calculated surface resulting in anovercorrection.

In addition, a meticulous thawing technique has to be adhered to. Thecomplications of thawing will influence postoperative corneal lenses.These include dense or opaque interfaces between the corneal lamella andthe host. The stroma of the resected cornea may also become opaque(Binder Arch Ophthalmol 100:101, 1982 and Jacobiec, Ophthalmology[Rochester] 88:1251, 1981; and Krumeich J H, Arch, AOO, 1981). There arealso wide variations in postoperative uncorrected visual acuity. Becauseof these difficulties, not many cases of myopic keratomileusis areperformed in the United States.

Surgical correction of hypermetropic keratomycosis involves the lamellarcornea as described for myopic keratomileusis. The surface of the corneais lathe cut after freezing to achieve higher refractive power. Thisprocedure is also infrequently performed in the United States because ofthe technical difficulties and has the greatest potential for lathingerrors. Many ophthalmologists prefer instead an alternative technique tothis procedure, that is keratophakia, i.e., implantation of a lensinside the cornea, if an intraocular lens cannot be implanted in theseeyes.

Keratophakia requires implantation of an artificial lens, either organicor synthetic, inside the cornea. The synthetic lenses are not toleratedwell in this position because they interfere with the nutrition of theoverlying cornea. The organic lenticulas, though better tolerated,require frozen lathe cutting of the corneal lenticule.

Problems with microkeratomies used for cutting lamellar cornea areirregular keratectomy or perforation of the eye. The recovery of visionis also rather prolonged. Thus, significant time is needed for theimplanted corneal lenticule to clear up and the best corrective visionsare thereby decreased because of the presence of two interfaces.

Application of ultraviolet and shorter wavelength lasers also have beenused to modify the cornea. These lasers are commonly known as excimerlasers which are powerful sources of pulsed ultraviolet radiation. Theactive medium of these lasers are composed of the noble gases such asargon, krypton and xenon, as well as the halogen gases such as fluorineand chlorine. Under electrical discharge, these gases react to buildexcimer. The stimulated emission of the excimer produces photons in theultraviolet region.

Previous work with this type of laser has demonstrated that farultraviolet light of argon-fluoride laser light with the wavelength of193 nm. can decompose organic molecules by breaking up their bonds.Because of this photoablative effect, the tissue and organic and plasticmaterial can be cut without production of heat, which would coagulatethe tissue. The early work in ophthalmology with the use of this type oflaser is reported for performing radial cuts in the cornea in vitro(Trokel, Am. J. Ophthalmol 1983 and Cotliar, Ophthalmology 1985).Presently, all attempts to correct corneal curvature via lasers arebeing made to create radial cuts in the cornea for performance of radialkeratotomy and correction of low myopia.

Because of the problems related to the prior art methods, there is acontinuing need for improved methods to correct eyesight.

SUMMARY OF THE INVENTION

Accordingly, it is a primary object of the present invention to providea method for modifying corneal curvature via introducing a transparentoptical material into an internal portion of the cornea.

Another object of the invention is to provide such a method that canmodify the curvature of a live cornea, thereby eliminating the need andcomplications of working on a frozen cornea.

Another object of the invention is to provide a method for improvingeyesight without the use of glasses or contact lenses, but rather bymerely modifying the corneal curvature.

Another object of the invention is to provide a method for modifyingcorneal curvature by using a source of laser light in a precise mannerand introducing a transparent optical material into the stroma of thecornea.

Another object of the invention is to provide a method that can modifythe curvature of a live cornea without the need of sutures.

Another object of the invention is to provide a method that can modifythe curvature of a live cornea with minimal incisions into theepithelium and Bowman's layer of the cornea.

Another object of the invention is to provide a method for modifying thecorneal curvature by ablating or coagulating the corneal stroma andintroducing a transparent optical material into the stroma of thecornea.

The foregoing objects are basically attained by a method of modifyingthe curvature of a patient's live cornea comprising the steps ofseparating an internal area of the live cornea into first and secondopposed internal surfaces, the first internal surface facing in theposterior direction and the second internal surface facing in theanterior direction, introducing a transparent optical material betweenthe surfaces, and recombining the first and second internal surfaces,the separating, directing and recombining steps taking place withoutfreezing the cornea. other objects, advantages, and salient features ofthe present invention will become apparent to those skilled in the artfrom the following detailed description, which, taken in conjunctionwith the annexed drawings, discloses preferred embodiments of theinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring now to the drawings which form a part of this originaldisclosure:

FIG. 1 is a side elevational view in section taken through the center ofan eye showing the cornea, pupil and lens;

FIG. 2 is a side elevational view in section similar to that shown inFIG. 1 except that a thin layer has been removed from the front of thecornea, thereby separating the cornea into first and second opposedinternal surfaces;

FIG. 3 is a diagrammatic side elevational view of the eye shown in FIG.2 with a laser beam source, diaphragm and guiding mechanism beinglocated adjacent thereto;

FIG. 4 is a side elevational view in section of an eye that has beentreated by the apparatus shown in FIG. 3 with ablation conducted in anannular area spaced from the center of the internal surface on thecornea;

FIG. 5 is a front elevational view of the ablated cornea shown in FIG.4;

FIG. 6 is a side elevational view in section showing the ablated corneaof FIGS. 4 and 5 with the thin layer previously removed from the corneareplaced onto the ablated area in the cornea, thereby increasing thecurvature of the overall cornea;

FIG. 7 is a side elevational view in section of an eye which has beenablated in the central area of the internal surface on the cornea;

FIG. 8 is a front elevational view of the cornea having the centralablated portion shown in FIG. 7;

FIG. 9 is a side elevational view in section of the ablated cornea ofFIGS. 7 and 8 in which the thin layer previously removed from the corneais replaced over the ablated area, thereby reducing the curvature of theoverall cornea;

FIG. 10 is a front elevational view of the adjustable diaphragm shown inFIG. 3 used for directing the laser beam towards the eye;

FIG. 11 is a front elevational view of the guiding mechanism shown inFIG. 3 having a rotatable orifice of variable size formed therein, fordirecting the laser beam towards the eye in a predetermined pattern;

FIG. 12 is a right side elevational view of the guiding mechanism shownin FIG. 11;

FIG. 13 is a right side elevational view in section taken along line13—13 in FIG. 11 showing the internal parts of the guiding mechanism;

FIG. 14 is a front elevational view of a modified guiding mechanismincluding a movable orifice;

FIG. 15 is a diagrammatic side elevational view of a second modifiedguiding mechanism for a laser beam including a universally supportedmirror and actuating motors used for moving the mirror and therebyguiding the laser beam in the predetermined pattern;

FIG. 16 is a diagrammatic side elevational view of a third modifiedguiding mechanism comprising a housing and a rotatable fiber opticcable;

FIG. 17 is an end elevational view of the housing and fiber optic cableshown in FIG. 16;

FIG. 18 is a diagrammatic side elevational view of a laser source,diaphragm and guiding mechanism for use in ablating the thin layerremoved from the cornea, which is shown supported by a pair of cups;

FIG. 19 is a front elevational view of a live cornea which has been cutwith a spatula to separate the central portion of the cornea into firstand second opposed internal surfaces in accordance with the presentinvention;

FIG. 20 is a side elevational view in section taken along line 20—20 ofthe cornea shown in FIG. 19;

FIG. 21 is a front elevational view of a cornea that has been cut asshown in FIG. 19 with ablation conducted in the central portion of thecornea by a laser;

FIG. 22 is a side elevational view in section taken along line 22—22 ofthe cornea shown in FIG. 21;

FIG. 23 is a side elevational view in section taken through the centerof an eye showing the ablated cornea of FIGS. 19-22 with the fiber optictip removed;

FIG. 24 is a side elevational view in section taken through the centerof an eye showing the ablated cornea of FIGS. 19-23 in its collapsedposition, thereby decreasing the curvature of the central portion of thecornea;

FIG. 25 is an enlarged, partial cross-sectional view of a cornea with afiber optic tip cutting, separating and ablating the cornea into firstand second opposed internal surfaces;

FIG. 26 is an enlarged, partial cross-sectional view of a cornea with afiber optic tip having an angled end for ablating the cornea;

FIG. 27 is an enlarged, partial cross-sectional view of a cornea with afiber optic tip having a bent end for ablating the cornea;

FIG. 28 is a front elevational view of a live cornea in which aplurality of radially extending cuts have been made with a spatula toseparate the cornea at each of the radially extending cuts into firstand second opposed internal surfaces in accordance with the presentinvention;

FIG. 29 is a front elevational view of a cornea in which the radiallyextending cuts shown in FIG. 28 have been ablated to create a pluralityof radially extending tunnels;

FIG. 30 is a side elevational view in section taken along line 30—30 ofthe cornea of FIG. 29 with the fiber optic tip removed;

FIG. 31 is a side elevational view in section taken along the center ofan eye showing the ablated cornea of FIGS. 28-30 in its collapsedposition, thereby decreasing the curvature of the central portion of thecornea;

FIG. 32 is a front elevational view of a live cornea in which aplurality of radially extending cuts have been made with a spatula toseparate the cornea at each of the radially extending cuts into firstand second opposed internal surfaces in accordance with the presentinvention;

FIG. 33 is a side elevational view in section taken along line 33—33 ofthe cornea of FIG. 32 with the spatula removed;

FIG. 34 is a front elevational view of a cornea that has been radiallycut as shown in FIGS. 32 and 33 with coagulation conducted at the endsof the radial cuts by a laser, thereby increasing the curvature of thecentral portion of the cornea;

FIG. 35 is a side elevational view in section taken along line 35—35 ofthe cornea of FIG. 34 with the laser removed and coagulation conductedat the ends of the radial cuts to increase the curvature of the centralportion of the cornea;

FIG. 36 is an enlarged, partial cross-sectional view of a cornea with adrill tip removing tissue therefrom;

FIG. 37 is a front elevational view of a live cornea that has been cutto form an intrastromal pocket and showing a tool for injecting orimplanting ocular material into the pocket;

FIG. 38 is an enlarged side elevational view in section taken throughthe center of an eye showing the intrastromal pocket over filled withocular material thereby increasing the curvature of the central portionof the cornea;

FIG. 39 is an enlarged side elevational view in section taken throughthe center of an eye showing the intrastromal pocket partially filledwith ocular material thereby decreasing the curvature of the centralportion of the cornea;

FIG. 40 is an enlarged side elevational view in section taken throughthe center of an eye showing the intrastromal pocket completely filledwith ocular material restoring the curvature of the central portion ofthe cornea to its original curvature;

FIG. 41 is a rear elevational view of an ocular implant or material inaccordance with the present invention for implanting into a cornea;

FIG. 42 is a cross-sectional view of the ocular implant or materialillustrated in FIG. 41 taken along section line 42—42;

FIG. 43 is an enlarged side elevational view in section taken throughthe center of an eye showing the intrastromal pocket with the ocularimplant or material of FIGS. 41 and 42 therein for increasing thecurvature of the central portion of the cornea;

FIG. 44 is an enlarged side elevational view in section taken throughthe center of an eye showing the intrastromal pocket with the ocularimplant or material of FIGS. 41 and 42 therein for decreasing thecurvature of the central portion of the cornea;

FIG. 45 is an enlarged side elevational view in section taken throughthe center of an eye showing the intrastromal pocket with the ocularimplant or material of FIGS. 41 and 42 therein for maintaining theoriginal curvature of the central portion of the cornea;

FIG. 46 is a front elevational view of a live cornea which has been cutto form a plurality of radial tunnels or pockets and showing a tool forinjecting or implanting ocular material into the tunnels;

FIG. 47 is an enlarged side elevational view in section taken throughthe center of the eye showing the radial tunnels or pockets of FIG. 46overfilled with ocular material thereby modifying the cornea andincreasing its curvature;

FIG. 48 is an enlarged side elevational view in section taken throughthe center of the eye showing the radial tunnels or pockets of FIG. 46underfilled with ocular material thereby modifying the cornea anddecreasing its curvature;

FIG. 49 is an enlarged side elevational view in section taken throughthe center of the eye showing the radial tunnels or pockets of FIG. 46completely filled with ocular material thereby modifying the cornea;

FIG. 50 is an enlarged side elevational view in section taken throughthe center of the eye showing one of the tunnels or pockets overfilledwith ocular material to increase the curvature of a selected portion ofthe cornea and another tunnel or pocket underfilled to decrease thecurvature of a selected portion of the cornea;

FIG. 51 is an enlarged side elevational view in section taken throughthe center of the eye showing one of the tunnels or pockets completelyfilled with ocular material to maintain a portion of the cornea at itsoriginal shape and another tunnel or pocket overfilled with ocularmaterial to increase the curvature of a selected portion of the cornea;

FIG. 52 is an enlarged side elevational view in section taken throughthe center of the eye showing one of the tunnels or pockets completelyfilled with ocular material to maintain a portion of the cornea at itsoriginal shape and another tunnel or pocket unfilled to collapse ordecrease the curvature of a selected portion of the cornea;

FIG. 53 is an enlarged side elevational view in section taken throughthe center of the eye showing one of the tunnels or pockets overfilledwith ocular material to increase the curvature of a selected portion ofthe cornea and another tunnel or pocket unfilled to collapse or decreasethe curvature of a selected portion of the cornea;

FIG. 54 is an exploded side elevational view in section taken throughthe center of an eye showing a thin layer or portion of the corneacompletely removed from the live cornea and the ocular material orimplant of FIGS. 41 and 42 positioned between the thin layer and theremainder of the live cornea;

FIG. 55 is an enlarged side elevational view in section taken throughthe center of the eye showing the ocular implant illustrated in FIGS. 41and 42 implanted in the cornea with the thin layer of the corneareplaced over the ocular implant to increase the curvature of thecornea;

FIG. 56 is an enlarged side elevational view in section taken throughthe center of the eye showing the ocular implant illustrated in FIGS. 41and 42 implanted in the cornea with the thin layer of the corneareplaced over the ocular implant to decrease the curvature of thecornea;

FIG. 57 is an enlarged side elevational view in section taken throughthe center of the eye showing the ocular implant illustrated in FIGS. 41and 42 implanted in the cornea with the thin layer of the corneareplaced over the ocular implant to maintain the cornea's originalcurvature;

FIG. 58 is an enlarged side elevational view in cross section throughthe center of an eye showing a circular cut or groove in the cornea andthe ocular implant of FIGS. 41 and 42 positioned between the separatedinternal layers, but before the separated internal layers are replacedor rejoined on the cornea;

FIG. 59 is a side elevational view in section through the center of theeye showing the outer surface of the cornea cut to form a flap having aportion still attached to the cornea to expose the intrastromal layersof the cornea;

FIG. 60 is a front elevational view of an ocular implant or material inaccordance with the present invention for implanting within theintrastromal area of the cornea; and

FIG. 61 is a cross-sectional view of the ocular implant or materialillustrated in FIG. 60 taken along section line 61—61.

DETAILED DESCRIPTION OF THE INVENTION

As seen in FIG. 1, an eye 10 is shown comprising a cornea 12, a pupil14, and a lens 16. If the combination of the cornea and lens does notprovide adequate vision, the cornea can be modified in accordance withthe invention to modify the refractive power of the combined corneal andlens system, to thereby correct vision. This is accomplished first byremoving a thin layer 18 from the center part of a patient's live cornea12 by cutting via a means for removing 19, such as a scalpel, viacutting, this thin layer being on the order of about 0.2 mm in thicknesswith the overall cornea being about 0.5 mm in thickness. Once the thinlayer 18 is cut and removed from the cornea, it exposes first and secondopposed internal surfaces 20 and 21 resulting from the surgicalprocedure. Advantageously, it is the exposed internal surface 20 on theremaining part of the cornea that is the target of the ablation via theexcimer laser. On the other hand, the cut internal surface 21 on theremoved thin layer of the cornea can also be the target of the laser, asillustrated in FIG. 18 and discussed in further detail hereinafter.

As seen in FIG. 3, the apparatus used in accordance with the inventioncomprises a source of a laser beam 22, an adjustable diaphragm 24, and aguiding mechanism 26, all aligned adjacent the eye 10 and supported on asuitable base 28.

The laser beam source 22 is advantageously an excimer laser of theargon-fluoride or krypton-fluoride type. This type of laser willphotoablate the tissue of the cornea, i.e., decompose it without burningor coagulating which would unduly damage the live tissue. This ablationremoves desired portions of the cornea and thereby allows formodification of the curvature thereof.

The adjustable diaphragm 24 seen in FIGS. 3 and 10 is essentially aconventional optical diaphragm with an adjustable central orifice 30that can be increased or decreased in radial size by a manipulation of alever 32 coupled to the diaphragm. The diaphragm is advantageouslysupported in a ring 34 that is in turn supported on a stand 36 on base28. The material forming the diaphragm is opaque to laser light and thuswhen the laser is directed towards the diaphragm, it will passtherethrough only via the orifice 30. The diaphragm 24 can be used inconjunction with the guiding mechanism 26, to be described in moredetail hereinafter, to restrict the size of the laser beam passing tothe guiding mechanism 26, or it can be used by itself to provideablation of the exposed internal surface 20 of a cornea at its center.

This is illustrated in FIGS. 7-9 where a substantially disc-shapedablated portion 38 is formed in the central exposed internal surface 20by directing the laser beam 22 through orifice 30 of the diaphragm 24.By modifying the size of the orifice, the disc-shaped ablated portion 38can be varied in size. Also, by varying the size of the orifice overtime, either a concave or convex ablated portion can be formed, asdesired. As shown in FIG. 9, once the ablated portion 38 is as desired,the previously removed thin layer 18 is replaced onto the cornea in theablated portion 38 and can be connected thereto via sutures 40.

Because the ablated portion 38 as seen in FIG. 7 is essentially auniform cylindrical depression in the exposed internal surface 20, whenthe thin corneal layer 18 is replaced, the curvature of the cornea isdecreased, thereby modifying the refractive power of the cornea and lenssystem.

As seen in FIG. 10, lever 32 is used to vary the size of orifice 30, andis capable of being manipulated by hand or by a suitable conventionalmotor, which can be coordinated to provide an expansion or contractionof the orifice as necessary over time.

As seen in FIGS. 3, 11, 12 and 13, the guiding mechanism 26 can beutilized in addition to or in place of the diaphragm 24 to guide thelaser light onto the cornea. This guiding mechanism 26 is especiallyadvantageous for forming an annular ablated portion 42 in surface 20 asseen in FIGS. 4-6 for increasing the overall curvature of the cornea.

As seen in FIGS. 4 and 5, this annular ablated portion 42 is spaced fromthe center of the exposed internal surface 20 and when the previouslyremoved thin corneal layer 18 is replaced and sutured, the thin layertends to be more convex, thereby modifying the overall curvature of thecornea.

As seen in FIGS. 11-13, the guiding mechanism 26 comprises a stand 44supporting a ring 46, this ring having a radially inwardly facing recess48 therein. A disc 50, which is opaque to laser light, is located insidethe ring and has a cylindrical extension 52 with an outwardly facingflange 54 rotatably and slidably received in the recess. On thecylindrical extension 52 which extends past ring 46 is an exteriortoothed gear 56 that is in engagement with a pinion 58 supported on ashaft 60 of a motor 62. Rotation of pinion 58 in turn rotates gear 56and disc 50.

The disc 50 itself has an elongated rectangular orifice 64 formedtherein essentially from one radial edge and extending radially inwardlypast the center point of the disc. Adjacent the top and bottom of theorifice 64 are a pair of parallel rails 66 and 68 on which a maskingcover 70, which is U-shaped in cross section, is slidably positioned.Thus, by moving the masking cover 70 along the rails, more or less ofthe orifice 64 is exposed to thereby allow more or less laser light topass therethrough and onto the cornea. Clearly, the larger the orifice,the larger the width of the annular ablated portion 42 will be. Byrotating the disc, the orifice 64 also rotates and thus the annularablated portion 42 is formed.

Embodiment of FIG. 14

Referring now to FIG. 14, a modified guiding mechanism 72 is shown whichis similar to guiding mechanism 26 shown in FIGS. 11-13 except that thesize of the orifice is not variable. Thus, the modified guidingmechanism 72 is comprised of a ring 74 on a stand 76, an opaque disc 78which is rotatable in the ring via a suitable motor, not shown, and aslidable masking cover 80. Disc 78 has a rectangular orifice 82extending diametrically there across with parallel rails 84 and 86 ontop and bottom for slidably receiving the masking cover 80 thereon, thiscover being U-shaped for engagement with the rails. The masking cover 80has its own orifice 88 therein which aligns with orifice 82 on the disc.Thus, by sliding the masking cover 80 along the rails of the disc, thelocation of the intersection of orifice 88 and orifice 82 can be variedto vary the radial position of the overall through orifice formed by thecombination of these two orifices. As in guiding mechanism 26, themasking cover 80 and disc 78 are otherwise opaque to laser light exceptfor the orifices.

Embodiment of FIG. 15

Referring now to FIG. 15, a second modified guiding mechanism 90 isshown for directing laser light from laser beam source 22 to the cornea12 along the desired predetermined pattern. This guiding mechanism 90comprises a mirror 92 universally supported on a stand 94 via, forexample, a ball 96 and socket 98 joint. This mirror 92 can be pivotedrelative to the stand through the universal joint by means of anysuitable devices, such as two small piezoelectric motors which engagethe mirror at 90° intervals. For example, such a piezoelectric motor 100having a plunger 102 coupled thereto and engaging the rear of the mirrorcan be utilized with a spring 104 surrounding the plunger andmaintaining the mirror in a null position. The motor 100 is rigidlycoupled to a base 106 via a stand 108. The second piezoelectric motor,not shown, can be located so that its plunger engages the rear of themirror 90° from the location of motor 100. By using these two motors,springs and plungers, the mirror 92 can be fully rotated in itsuniversal joint to direct the laser beam from source 22 onto the cornea12 to ablate the cornea in a predetermined pattern.

Embodiment of FIGS. 16-17

Referring now to FIGS. 16 and 17, a third modified guiding mechanism 111is shown for ablating a cornea 12 via directing laser light from lasersource 22. This modified guiding mechanism 111 basically comprises acylindrical housing 113 having an opaque first end 115 rotatablyreceiving the end of a fiber optic cable 117 therein. The second end 119of the housing comprises a rotatable opaque disc having a flange 121engaging the housing and an external gear 123 which in turn engagespinion 125, which is driven via shaft 127 and motor 129. Thus, rotationof the pinion results in rotation of gear 123 and thus the opaque secondend 119 of the housing. This second end 119 has a diametrically orientedrectangular orifice 131 therein which receives the other end of thefiber optic cable 117 therein. That end of the fiber optic cable iseither dimensioned so that it fits fairly tightly into the orifice orthere is an additional suitable assembly utilized for maintaining thefiber optic cable end in a predetermined position in the orifice duringrotation of the second end. However, this end would be movable radiallyof the orifice to change the position of the annular ablated portionformed by utilizing this guiding mechanism.

Embodiment of FIG. 18

Referring now to FIG. 18, rather than ablating the exposed internalsurface 20 on the cornea 12, the inner surface 133 of the removed thincorneal layer 18 can be ablated utilizing the apparatus shown in FIG.18. Likewise, the apparatus of FIG. 18 can be used on an eye bank cornearemoved from the eye and then positioned in the patient's eye to modifythe curvature of the patient's combined corneal structure. Thisapparatus as before includes the source of the laser light 22, anadjustable diaphragm 24, and a guiding mechanism 26. In addition, anassembly 134 is utilized to support the rather flimsy removed thincorneal layer. This assembly 134 comprises a pair of laser lighttransparent cups 136 and 138 that are joined together in a sealingrelationship via clamps 140 and engage therebetween the outer peripheryof the thin corneal layer 18. Each of the cups has an inlet pipe 142,144 for injecting pressurized air or suitable fluid into each via pumps146 and 148. By using this pressurized container, the thin corneal layer18 is maintained in the desired curvature so that the laser beam canprovide a precise ablated predetermined pattern therein. In order tomaintain the curvature shown in FIG. 18, the pressure on the right handside of the thin layer is slightly greater than that on the left handside.

Once the thin corneal layer 18 is suitably ablated as desired, it isreplaced on the exposed internal surface 20 of the cornea and varies thecurvature of the overall cornea as described above and illustrated inFIGS. 4-9.

Embodiment of FIGS. 19-27

Referring now to FIGS. 19-27, a patient's live in situ eye 110 is shownfor the treatment of myopia in accordance with the present invention.Eye 110 includes a cornea 112, a pupil 114, and a lens 116, and istreated in accordance with the present invention without freezing thecornea.

Correction of myopia can be achieved by decreasing the curvature of theouter surface of cornea 112 (i.e., flattening the central portion of thecornea). This is accomplished by first cutting an incision 118 into theepithelium of cornea 112. Incision 118 may be curved or straight, and ispreferably about 2.0-3.0 mm long and about 3.0-6.0 mm away from thecenter of cornea 112. A laser or spatula (i.e., a double-edge knife) maybe used to make incision 118 in cornea 112.

As seen in FIGS. 19 and 20, once incision 118 is made, a spatula 120 isinserted into incision 118 to separate an internal area of live cornea112 into first and second opposed internal surfaces 122 and 124, therebycreating an intrastromal or internal pocket 126. First internal surface122 faces in the posterior direction of eye 110, while second internalsurface 124 faces in the anterior direction of eye 110, and both ofthese surfaces extend radially relative to the center of the cornea.

As seen in FIGS. 19 and 20, pocket 126 is created by moving spatula 120back and forth within an intrastromal area of cornea 112. It isimportant when creating pocket 126 to keep spatula 120 in substantiallya single plane and substantially tangential to the cornea's internalsurfaces to prevent intersecting and rupturing the descemet or Bowman'smembrane.

Preferably, spatula 120 is about 3.0-12.0 mm long with a thickness ofabout 0.1-1.0 mm, and a width of about 0.1-1.2 mm. Spatula 120 may beslightly curved, as seen in FIG. 20, or may be straight.

While a spatula 120 is shown in FIGS. 19 and 20 for separating theinternal surfaces of cornea 112, a fiber optic cable coupled to a laserbeam source may be used instead of spatula 120 to separate cornea 112into first and second opposed internal surfaces 122 and 124.

As seen in FIGS. 21 and 22, after pocket 126 is formed, a fiber opticcable tip 130 coupled to a fiber optic cable 132, which is in turncoupled to a laser, is then inserted through incision 118 and intopocket 126 for ablating a substantially circular area of cornea 112,thereby removing a substantially disc-shaped portion of cornea 112 toform a disc-shaped cavity 126′. The laser beam emitted from tip 130 maybe directed upon either first internal surface 122, second internalsurface 124, or both, and removes three-dimensional portions therefromvia ablation. The fiber optic cable can be solid or hollow as desired.

The laser source for fiber optic cable 132 is advantageously a longwavelength, infrared laser, such as a CO₂, an erbium or holmium laser,or a short wavelength, UV-excimer laser of the argon-fluoride orkrypton-fluoride type. This type of laser will photoablate theintrastromal tissue of the cornea, i.e., decompose it without burning orcoagulating.

FIGS. 25-27 illustrate three different configurations of the tip of afiber optic cable for ablating the cornea. In FIG. 25, tip 130 has asubstantially straight end for directing the laser beam parallel to thetip. As seen in FIG. 26, tip 130′ has an end with an angled surface fordirecting the laser beam at an acute angle of preferably 450 relative tothe tip to aid in ablating the cornea as desired. In FIG. 27, tip 130″has a curved end for bending the laser beam to aid ablating the corneaas desired.

As seen in FIG. 23, cornea 112 is shown with the substantiallydisc-shaped cavity 126′ formed at the center of cornea 112 just aftertip 130 has been removed and prior to cornea 112 collapsing orflattening. The disc-shaped cavity 126′ can be varied in size and shape,depending upon the amount of curvature modification needed to correctthe patient's eyesight. Accordingly, any three-dimensional intrastromalarea of the cornea may be removed to modify the cornea as desired. Theintrastromal area removed can be uniform or non-uniform. For example,more material can be removed from the periphery of the cornea than fromthe center portion. Alternatively, more material can be removed from thecenter portion than from the peripheral area. The removal of peripheralportions of the cornea result in an increase of the curvature of thecenter portion of the cornea after the collapse of the peripheral area.

As seen in FIG. 24, after pocket 126 is ablated and tip 130 removed, theablated cavity 126′ then collapses under normal eye pressure torecombine ablated first and second internal surfaces 122 and 124together. This collapsing and recombining of the intrastromal area ofthe cornea decreases the curvature of the central portion of cornea 112from its original shape shown in broken lines to its new shape as seenin FIG. 24. After a period of time, depending on the patient's healingabilities, the ablated surfaces heal and grow back together, resultingin a permanent modification of the corneals curvature.

Embodiment of FIGS. 28-31

Referring now to FIGS. 28-31, an eye 210 is shown for the treatment ofmyopia in accordance with another embodiment of the present invention,and includes a cornea 212, a pupil 214, and a lens 216, the cornea beingtreated without freezing it. In this embodiment, correction of myopia isaccomplished by first making a plurality of radially directedintrastromal incisions 218 with a flat pin or blade spatula 220. Theseincisions 218 separate the cornea 218 into first and second opposedinternal surfaces 222 and 224 at each of the incisions 218. Firstinternal surfaces 222 face in the posterior direction of eye 210, whilesecond internal surfaces 224 face in the anterior direction of eye 210,and both extend radially relative to the center of the cornea. Spatula220 may have a straight or curved blade with a maximum diameter of about0.1-0.2 mm. A laser may be used instead of spatula 220 to make incisions218, if desired.

Incisions or unablated tunnels 218 extend generally radially towards thecenter of cornea 212 from its periphery. Preferably, incisions 218 stopabout 3.0 mm from the center of cornea 212, although incisions 218 mayextend to the center of cornea 212, depending upon the degree of myopia.Incisions 218 will normally extend about 3.0-10.0 mm in length, againdepending on the amount of change desired in curvature of cornea 112.While only radial incisions have been shown, it will be apparent tothose skilled in the art that the incisions may be non-radial, curved,or other shapes. When creating incisions 218, it is important to keepthe spatula 220 in substantially a single plane so as not to intersectand puncture the descemet or Bowman's membrane.

Once intrastrcmal incisions 218 have been created with spatula 220, afiber optic cable tip 230 coupled to a fiber optic cable 232 and a laseris then inserted into each of the incisions 218 for ablating tunnels 226to the desired size. The laser beam emitted from tip 230 may be directedupon either first internal surface 222, second internal surface 224, orboth for ablating tunnels 226 and removing three-dimensional portionsfrom these surfaces.

The laser source for cable 232 is advantageously similar to the lasersource for cable 132 discussed above.

Referring now to FIGS. 30 and 31, a pair of ablated tunnels 226 areshown. In FIG. 30, cornea 212 is shown with ablated tunnels 226 justafter tip 230 has been removed and prior to tunnels 226 collapsing orflattening. In FIG. 31, cornea 212 is shown after ablated tunnels 226have collapsed to recombine first and second internal surfaces 222 and224, thereby flattening cornea 212. In other words, this collapsing andrecombining of the intrastromal area of the cornea decreases thecurvature of the central portion of cornea 212 from its original shapeshown in broken lines to its new shape as seen in FIG. 31. By collapsingintrastromal tunnels, this allows the outer surface of the cornea torelax, i.e., decrease surface tension, thereby permitting flattening ofthe cornea.

Embodiment of FIGS. 32-35

Referring now to FIGS. 32-35, an eye 310 is shown for the treatment ofhyperopia in accordance with another embodiment of the presentinvention. Eye 310 includes a cornea 312, a pupil 314, and a lens 316.Correction of hyperopia can be achieved by increasing the curvature ofthe outer surface of cornea 312 (i.e., making the central portion of thecornea more curved), without freezing the cornea.

This is accomplished by making a plurality of intrastromal incisions ortunnels 318 with a spatula 320 to form first and second opposed internalsurfaces 322 and 324. Tunnels 318 extend substantially radially towardsthe center of cornea 312. While eight equally spaced, radial tunnels 318are shown, it will be apparent to those skilled in the art that more orfewer tunnels with varying distances apart may be made, depending uponthe amount of curvature modification needed.

The initial step of making incisions or tunnels 318 of FIGS. 32-35 issimilar to the initial step of making incisions 218 of FIGS. 28-31.Accordingly, spatula 320 is similar to spatula 220 discussed above.Likewise, a laser may be used to make incisions or tunnels 318 insteadof spatula 320.

Once tunnels 318 are created, a fiber optic cable tip 330 extending fromfiber optic cable 332 is inserted into each tunnel 318 to direct a laserbeam on either first internal surface 322, second internal surface 324,or both internal surfaces to coagulate an intrastromal portion of cornea312. As seen in FIG. 34, a point 326 at the end of each of the tunnels318 is coagulated. Preferably, coagulation points 326 lie substantiallyon the circumference of a circle concentric with the center of cornea312. The size of the circle forming coagulation points 326 depends uponthe amount of curvature modification needed. Likewise, the number ofcoagulation points and their positions in the cornea depend upon thedesired curvature modification needed.

Coagulating intrastromal points of the cornea 312, such as coagulationpoints 326, with a laser causes those points of the cornea, andespecially the collagen therein, to heat up and shrink. This localizedshrinkage of the intrastromal portion of the cornea causes the outersurface of the cornea to be tightened or pulled in a posterior directionat each of the coagulation points, and thereby causes an increase in theoverall curvature of the cornea as seen in FIG. 35. Coagulation, ratherthan ablation, is accomplished by using a laser having a wavelengthwhich essentially cooks the corneal tissue and which is between thewavelengths associated with long infrared light and short ultravioletlight.

Embodiment of FIG. 36

As seen in FIG. 36, rather than using a laser to remove corneal tissuein the cavities 126 formed in the cornea 112 or to form those cavities,a rotating drill tip 400 suitably coupled to a rotary or oscillatingpower source can be used to ablate the tissue by cutting. Likewise, anyother suitable mechanical device can be used to remove the cornealtissue or form the cavities. A suitable evacuation device, such as avacuum tube, can also be used to aid in evacuating from the cavity thetissue removed from the cornea.

Embodiment of FIGS. 37-45

Referring now to FIGS. 37-45, a patient's live in situ eye 410 is shownfor the treatment of hyperopia or myopia and/or improving a patient'svision by removing opaque portions of the cornea in accordance with thepresent invention. The eye 410 of FIGS. 37-40 and 43-45 includes acornea 412, a pupil 414 and a lens 416, and is treated in accordancewith the present invention without freezing any portion of cornea 412.

Correction of myopia and hyperopia can be achieved by modifying thecurvature of the outer surface of cornea 412, i.e., flattening thecentral portion of a cornea in the case of myopia or increasing thecurvature in the case of hyperopia. This is accomplished by firstcutting an incision 418 into the epithelium of cornea 412 as seen inFIG. 37. Incision 418 may be curved or straight, and is preferably about2.0-3.0 mm long and about 3.0-6.0 mm away from the center of cornea 412.A laser or a doubleedge knife may be used to make incision 418 in cornea412.

As seen in FIGS. 37-40 and 43-45, once incision 418 is made, a spatulaor laser probe is inserted into incision 418 to separate an internalarea of live cornea 412 into first and second opposed internal surfaces422 and 424, thereby creating an intrastromal or internal pocket 426 asin the previous embodiment of FIGS. 19-27. First internal surface 422faces in the posterior direction of eye 410, while second internalsurface 424 faces in the anterior direction of eye 410, and both ofthese surfaces extend radially relative to the center of the cornea 412.

Pocket 426 can have corneal tissue removed from either or both ofinternal surfaces 422 and 424. In other words, internal surfaces 422 and424 of intrastromal pocket 426 can be ablated or cut to define a cavity.The ablating or removing of the internal surfaces 422 and 424 of cornea412 is particularly desirable to remove opaque areas of cornea 412.Alternatively, the internal surfaces 422 and 424 of cornea 412 can beremoved by a scalpel or a diamond tipped drill similar to theembodiments discussed above. Pocket 426 can be created by substantiallythe same method as previously discussed. of course, incision 418 andpocket 426 can be made in one single step by a laser or a cuttingmechanism. Alternatively, none of the corneal tissue can be removed frominternal surfaces 422 and 424.

As shown in FIGS. 37-40 and 43-45, once the pocket 426 is formed, anocular material 428 or 430 is inserted into pocket 426 by a tool 450.Ocular material 428 or 430 as used herein refers to transparent fluidsor solids or any combination thereof. In the examples of FIGS. 38-40,the ocular material is a gel or fluid type material 428, which can beinjected into pocket 426 via tool 450. In other words, in the examplesof FIGS. 38-40, tool 450 is a needle for injecting ocular material 428into pocket 426. In examples of FIGS. 43-45, the ocular material is aflexible, resilient ring shaped member 430.

In either case, ocular material 428 or 430 can have either the samerefractive index as the intrastromal tissue of cornea 412 or a differentrefractive index from the intrastromal tissue of cornea 412. Thus, thevision of the patient can be modified by curvature modification and/orby changing the refractive index. Moreover, the patient's vision can bemodified by merely removing opaque portions of the cornea and replacingthem with ocular material with a refractive index the same as theintrastromal tissue of cornea 412.

In the examples of FIGS. 38-40 using ocular material 428, pocket 426 canbe overfilled, partially filled, or completely filled to modify thecornea as needed. The cavity of pocket 426 can be filled completely withthe ocular material to restore the normal curvature of cornea 426 asseen in FIG. 40. The amount of ocular material introduced to pocket 426can be increased to increase the curvature of the cornea from theoriginal curvature to treat hyperopia as seen in FIG. 38. Alternatively,the amount of the ocular material introduced to pocket 426 can bereduced to decrease the curvature or flatten cornea 412 from theoriginal curvature to treat myopia as seen in FIG. 39. This method issuitable for correctly vision of 12 diopters or more. After the pocket426 is filled, the internal surfaces 422 and 424 of pocket 426 cometogether to encapsulate ocular material 428 within cornea 412. Thesurfaces heal and grow back together, resulting in a permanentmodification of the corneals curvature.

The ocular material 428 injected into pocket 426 can be any suitablematerial that is bio-compatible and does not visually interfere with thepatient's eyesight. Preferably, the ocular material 428 of FIGS. 38-40is a transparent gellable collagen such as gelatin in an injectable formwhich is available from various commercial sources as known in the art.Generally, the collagen to be used in the present invention is a type Icollagen. Of course, ocular material 428 can be a transparent ortranslucent bio-compatible polymer gel such as a silicone gel or aninjectable polymethylmethacrylate. Preferably, ocular material 428 is apolymeric material that is transparent, flexible, and hydrophilic. Itwill be understood by those skilled in the art from this disclosure thatocular material 428 can be any suitable polymeric material. Of course,ocular material 428 can be a flexible solid or semi-solid material asshown in the examples of FIGS. 41-45 discussed below regarding ocularmaterial 430 which can be made from collagen or synthetic polymers suchas acrylic polymers, silicones and polymethylmethacrylates.

Referring now to the examples of FIGS. 43-45 using a solid or semi-solidocular material or implant 430, tool 450 is utilized to insert ocularmaterial or implant 430 through the small opening formed by incision 418in the external surface of cornea 412, as seen in FIG. 37 so that ocularmaterial or implant 430 can be implanted into pocket 426 and centeredabout the main optical axis of eye 410. Ocular material or implant 430is preferably a resilient, flexible member, which can be folded forinsertion into pocket 426 through the small opening formed by incision418.

The ocular implant 430 is made from a bio-compatible transparentmaterial. Preferably, ocular implant 430 is made from any suitabletransparent polymeric material. Suitable materials include, for example,collagen, silicone, polymethylmethacrylate, acrylic polymers, copolymersof methyl methacrylate with siloxanylalkyl methylacrylates, celluloseacetate butyrate and the like. Such materials are commercially availablefrom contact lens manufacturers. For example, optical grade siliconesare available from Allergan, Alcon, Staar, Chiron and bolab. Opticalgrade acrylics are available from Allergan and Alcon. A hydrogel lensmaterial consisting of a hydrogel optic and polymethylmethacrylate isavailable from Staar.

Similar to the fluid type ocular material 428, discussed above, solid orsemi-solid ocular material or implant 430 can overfill, partial fill orcompletely fill pocket 426 to modify cornea 412 as needed. Whileablation or removal of intrastromal tissue of pocket 426 is required fordecreasing the curvature of cornea 412 as seen in FIG. 44, or formaintaining the original curvature of cornea 412 as seen in FIG. 45,such ablation or removal of intrastromal tissue of pocket 426 is notnecessary for increasing the curvature of cornea 412. In any event, theamount of intrastromal tissue to be removed, if any, from pocket 426depends on the shape of ocular material 430 and the desired resultantshape of cornea 412.

As seen in FIGS. 41 and 42, ocular material or implant 430 has asubstantially annular ring shape with a center opening or circular hole432. Center opening 432 allows intrastromal fluids to pass throughocular material or implant 430. Preferably, ocular material 430 has acircular periphery with an outer diameter in the range of about 3.0 mmto about 9.0 mm. Center opening 432 preferably ranges from about 1.0 mmto about 8.0 mm. The thickness of ocular material 430 is preferablyabout 20 microns to about 1000 microns.

In the embodiment of FIGS. 41-45, ocular material or implant 430 has aplanar face 434 and a curved face 436. Planar face 434 forms afrustoconically shaped surface, which faces inwardly towards the centerof eye 410 in a posterior direction of eye to contact internal surface424 of pocket 426. Curved face 436 can be shaped to form a correctivelens or shaped to modify the curvature cornea 412 as seen in FIGS. 43and 44. Of course, ocular material 430 can be shaped to replace opaqueareas of cornea 412, which have been previously removed, and/or to forma corrective lens without changing the curvature of cornea 412 as seenin FIG. 45.

When center opening 432 is about 2.0 mm or smaller, center opening 432acts as a pin hole such that the light passing through is alwaysproperly focused. Accordingly, ocular material 430 with such a smallcenter opening 432 can be a corrective lens, which is not severelyaffected by center opening 432. However, when ocular material 430 hasits center opening 432 greater than about 2.0 mm, then ocular material430 most likely will have the same refractive index as the intrastromaltissue of cornea 412 for modifying the shape of cornea 412 and/orreplacing opaque areas of the intrastromal tissue of cornea 412. Ofcourse, all or portions of ocular material 430 can have a refractiveindex different from the intrastromal tissue of cornea 412 to correctastigmatisms or the like, when center opening 432 is greater than about2.0 mm.

The amount of curvature modification and/or the corrective powerproduced by ocular material 430 can be varied by changing the thickness,the shape, the outer diameter and/or the size of the center opening 432.Moreover, instead of using a continuous, uniform ring as illustrated inFIGS. 41 and 42, ocular material 430 can be a ring with non-uniformcross-section in selected areas as necessary to correct the patient'svision. In addition, ocular material 430 could be replaced with aplurality of separate solid or semi-solid ocular implants at selectedlocations within pocket 426 of cornea 412.

Embodiment of FIGS. 46-53

Referring now to FIGS. 46-53, an eye 510 is shown for the treatment ofhyperopia or myopia and/or improving vision by removing opaque portionsof the cornea, in accordance with another embodiment of the presentinvention. Eye 510 includes a cornea 512, a pupil 514, and a lens 516.As in the previous embodiments, cornea 512 is treated without freezingit.

In this embodiment, correction of hyperopia or myopia or removal ofopaque portions can be accomplished by first making a plurality ofradially directed intrastromal incisions 518 with a flat pin, laser orblade spatula similar to the procedure mentioned above discussing theembodiment of FIGS. 28-31. These incisions 518 separate cornea 512 intofirst and second opposed internal surfaces 522 and 524, respectively, ateach of the incisions 518. First internal surfaces 522 face in theposterior direction of eye 510, while second internal surfaces 524 facein the anterior direction of eye 510, and both extend radially relativeto the center of cornea 512.

Incisions or unablated tunnels 518 extend generally radially towards thecenter of cornea 512 from its periphery. Preferably, incisions 518 stopabout 3.0 mm from the center of cornea 512, although incisions 518 mayextend to the center of cornea 512, depending upon the degree ofhyperopia or myopia. Incisions 518 will normally extend about 3.0-10.0mm in length, again depending on the amount of change desired incurvature of cornea 512. While only radial incisions have been shown, itwill be apparent to those skilled in the art that the incisions may benon-radial, curved, or other shapes. When creating incisions 518, it isimportant to keep the spatula or laser in substantially a single planeso as not to intersect and puncture the descemet or Bowman's membrane.

Once intrastromal incisions 518 have been created, a fiber optic cabletip coupled to a fiber optic cable and a laser can be optionallyinserted into each of the incisions 518 for ablating tunnels 526 to thedesired size, if needed or desired. The laser beam emitted from the tipmay be directed upon either first internal surface 522, second internalsurface 524, or both for ablating tunnels 526 to sequentially andincrementally remove three-dimensional portions from these surfaces. Thelaser source for the cable is advantageously similar to the laser sourcefor the cable as discussed above. Alternatively, a drill or othersuitable micro-cutting instruments can be used to sequentially andincrementally remove portions of the cornea.

Referring to FIG. 46, a plurality of radial tunnels 526 are shown with asuitable tool 550 projecting into one of the tunnels 526 for introducingoptical material 528 into tunnels 526 to modify cornea 512. Ocularmaterial 528 as used herein refers to transparent fluids or solids orany combination thereof. In the examples of FIGS. 47-53, ocular material528 is a gel or fluid type material, which can be injected into pockets526 via tool 550. Preferably, in this case, tool 550 is a needle forinjecting ocular material 528 into pockets 526. Of course as in thepreceding embodiment, a solid implant or ocular material may beintroduced into pockets 526. Also, ocular material 528 can have either arefractive index, which is different or the same as the intrastromaltissue of cornea 512 as needed and/or desired, whether the ocularmaterial is a gel, a solid or any combination thereof.

As shown in FIG. 47, optical material 528 injected into the ablatedtunnels 526 expands the outer surface of cornea 512 outward to change ormodify the curvature of the central portion of cornea 512 from itsoriginal shape shown in broken lines to its new shape shown in fulllines.

As seen in FIGS. 47-53, the various radial tunnels 526 can be filledwith ocular material 528 to overfill pockets 526 (FIG. 47), underfillpockets 526 (FIG. 48) or completely fill pockets 526 (FIG. 49). Thus, byintroducing various amounts of optical material into pockets 526, thecurvature of cornea 512 can be varied at different areas. Similarly,selected tunnels 526 can be overfilled or completely filled at selectedareas, while other selected tunnels can be partially filled, completelyfilled or unfilled to collapse or decrease the curvature of cornea 512at other selected areas as shown in FIGS. 50-53. The selectivealteration of the curvature in different areas of the cornea areparticularly desirable in correcting astigmatisms.

In the embodiment illustrated in FIGS. 47-53, the intrastromal areas oftunnels 526 are preferably ablated by a laser or cut by a micro-cuttinginstrument for sequentially and incrementally removing three-dimensionalportions of cornea 512 to form tubular pockets from tunnels 526.However, as in the previous embodiment of FIGS. 37 and 38, the incisions518 can be filled with ocular material without previously ablating orcutting the internal surfaces 522 and 524 of cornea 512 to expand thecornea 512 for increasing its curvature. Ablating the internal surfacesof the cornea is advantageous to remove opaque areas of the cornea whichcan then be filled with the ocular material.

As shown in FIGS. 48 and 50, the amount of ocular material 528introduced into the ablated areas of pockets 526 can be less then theamount of ablated material to reduce the curvature of cornea 512.Alternatively, the amount of ocular material 528 introduced into theablated areas of pockets 526 can completely fill pockets 526 to retainthe original curvature of cornea 512 as seen in FIGS. 49, 51 and 52.

Embodiment of FIGS. 54-57

Referring now to FIGS. 54-57, an eye 610 is shown for treatment ofhyperopia, myopia and/or removal of opaque portions in accordance withanother embodiment of the invention using an implant or ocular material630. As shown, the eye 610 includes a cornea 612, a pupil 614 and a lens616. As in the previous embodiments, the live eye 610 is treated withoutfreezing cornea 612 or any part thereof.

In this embodiment, a thin layer 618 of cornea 612 is first removed fromthe center portion of a patient's live cornea 612 by cutting using ascalpel or laser. The thin layer 618 is typically on the order of about0.2 mm in thickness with overall cornea being on the order of about 0.5mm in thickness. Once the thin layer 618 is removed from cornea 612, itexposes first and second opposed internal surfaces 622 and 624.Generally, either or both of the internal surfaces 622 and/or 624 arethe target of the ablation by the excimer laser. Alternatively, tissuefrom the internal surfaces 622 and/or 624 can be removed by a mechanicalcutting mechanism, or substantially no tissue is removed from thecornea.

As illustrated in FIG. 54, a disc-shaped portion 626 is removed frominternal surface 624 by a laser beam or other cutting mechanism. In thisembodiment, internal surface 624 is shaped to include a concave annularportion 627. The method and laser apparatus as described above in theembodiment of FIGS. 1-10 can be used for removing tissue from cornea 612in substantially the same manner.

After the exposed internal surface 622 or 624 of cornea 612 is ablated,if necessary, an annular ring shaped implant or ocular material 630 isplaced on ablated portion 628 of cornea 612. The previously removed thinlayer 618 of cornea 612 is then replaced onto ablated portion 626 ofcornea 612 to overlie implant or ocular material 630 and thenreconnected thereto. The resulting cornea can have a modified curvaturethereby modifying the refractive power of the cornea and lens system asseen in FIGS. 55 and 56, or the original curvature with opaque areasremoved and/or modified refractive power as seen in FIG. 57.

The ocular implant or material 630 in the embodiment shown in FIGS.54-57 has a substantially annular ring shape, and is substantiallyidentical to the implant or ocular material 430 discussed above. Thus,implant 430 will not be illustrated or discussed in detail whenreferring to the procedures or methods of FIGS. 54-57.

The outer diameter of ocular implant or material 630 can be about 3-9mm, while the inner opening 632 is generally about 1-8 mm. The thicknessof ocular implant 630 is preferably about 20 to about 1000 microns.Ocular implant 630 has a planar face 644 forming a frustoconicallyshaped surface, which faces inwardly towards the center of eye 610 in aposterior direction of eye 610 to contact the exposed inner surface 620of the cornea 612. The opposite face 646 is preferably a curved surfacefacing in an anterior direction of eye 610 as shown. The ocular implant630 can be shaped to form a corrective lens or shaped to modify thecurvature of the cornea. Similarly, the implant can be used to replaceopaque areas of the cornea which have been previously removed byablation or other means.

In the embodiment shown, ocular implant 630 preferably has asubstantially uniform shape and cross-section. Alternatively, ocularimplant 630 can be any suitable shape having either a uniform and/ornon-uniform cross-section in selected areas as necessary to correct thepatient's vision. For example, an ocular implant can be used having acircular or triangular cross section. In this manner, the curvature of acornea can be modified at selected areas to correct various opticaldeficiencies, such as, for example, astigmatisms. Ocular implant 630 canbe a corrective lens with the appropriate refractive index to correctthe vision of the patient. The ocular implant 630 is made from abio-compatible transparent material. Preferably, ocular implant 630 ismade from any suitable transparent polymeric material. Suitablematerials include, for example, collagen, silicone,polymethylmethacrylate, acrylic polymers, copolymers of methylmethacrylate with siloxanylalkyl methylacrylates, cellulose acetatebutyrate and the like. Such materials are commercially available fromcontact lens manufacturers. For example, optical grade silicones areavailable from Allergan, Alcon, Staar, Chiron and Iolab. Optical gradeacrylics are available from Allergan and Alcon. A hydrogel lens materialconsisting of a hydrogel optic and polymethylmethacrylate is availablefrom Staar.

Hydrogel ocular implant lenses can be classified according to thechemical composition of the main ingredient in the polymer networkregardless of the type or amount of minor components such ascross-linking agents and other by-products or impurities in the mainmonomer. Hydrogel lenses can be classified as (1) 2-hydroxyethylmethacrylate lenses; (2) 2-hydroxyethylmethacrylate-N-vinyl-2-pyrrolidinone lenses; (3) hydrophilic-hydrophobicmoiety copolymer lenses (the hydrophilic components is usuallyN-vinyl-2-pyrrolidone or glyceryl methacrylate, the hydrophobiccomponents is usually methyl methacrylate); and (4) miscellaneoushydrogel lenses, such as lenses with hard optical centers and softhydrophilic peripheral skirts, and two-layer lenses.

Alternatively, ocular implant 630 can be elongated or arcuate shaped,disc shaped or other shapes for modifying the shape and curvature ofcornea 612 or for improving the vision of eye 610 without modifying thecurvature of cornea 612. Similarly, ocular implant 630 can be placed inthe intrastromal area of the cornea 612 at a selected area to modify thecurvature of the cornea and correct the vision provided by the corneaand lens system. In the embodiment shown in FIGS. 54-57, thin layer 618of cornea 612 is completely removed to expose the internal surfaces 622and 624 of cornea 612.

Embodiment of FIG. 58

An alternative method of implanting ocular material or implant 630 intoan eye 710 is illustrated in FIG. 58. Specifically, ocular material orimplant 630 is implanted into cornea 712 of eye 710 to modify thepatient's vision. In particular, this method can be utilized for thetreatment of hyperopia, myopia or removal of opaque portions of thecornea. As in the previous embodiments, the treatment of eye 510 isaccomplished without freezing cornea 512 or any portion thereof.

In this method, a ring or annular incision 718 is formed in cornea 712utilizing a scalpel, laser or any cutting mechanism known in the art.The scalpel, laser or cutting mechanism can then be used to cut orablate an annular-shaped intrastromal pocket 726 in cornea 712 as neededand/or desired. Accordingly, an annular groove is now formed forreceiving ocular material or implant 630 which is discussed above indetail.

The annular groove formed by annular incision 718 separates cornea 712into first and second opposed internal surfaces 722 and 724. Firstinternal surface 722 faces in the posterior direction of eye 710, whilesecond internal surface 724 faces in the anterior direction of eye 710.optionally, either internal surfaces 722 or 724 can be ablated to makethe annular groove or pocket 726 larger to accommodate ocular implant630.

The portion of cornea 712 with internal surface 722 forms an annularflap 725, which is then lifted and folded away from the remainder ofcornea 712 so that ocular implant of material 630 can be placed intoannular pocket 726 of cornea 712 as seen in FIG. 58. Now, corneal flap725 can be folded over ocular implant or material 630 and reconnected tothe remainder of cornea 712 via sutures or the like. Accordingly, ocularimplant or material 630 is now encapsulated within cornea 712.

As in the previous embodiments, ocular implant or material 630 canmodify the curvature of the exterior surface of cornea 712 so as toeither increase or decrease its curvature, or maintain the curvature ofthe exterior surface of cornea 712 at its original curvature. In otherwords, ocular implant or material 630 can modify the patient's vision bychanging the curvature of the cornea 712 and/or removing opaque portionsof the cornea and/or by acting as a corrective lens within the cornea.

Embodiment of FIG. 59

Another embodiment of the present invention is illustrated utilizingocular implant 630 in accordance with the present invention. Morespecifically, the method of FIG. 59 is substantially identical to themethods discussed above in reference to FIGS. 54-57, and thus, will notbe illustrated or discussed in detail herein. Rather, the onlysignificant difference between the methods discussed regarding FIGS.54-57 and the method of FIG. 59 is that the thin layer 816 of FIG. 59 isnot completely removed from cornea 812 of eye 810.

In other words, thin layer 818 of cornea 812 is formed by using ascalpel or laser such that a portion of layer 818 remains attached tothe cornea 812 to form a corneal flap. The exposed inner surface 820 oflayer 818 or the exposed internal surface 824 of the cornea can beablated or cut with a laser or cutting mechanism as in the previousembodiments to modify the curvature of the cornea. Ocular implant 630can then be placed between internal surfaces 820 and 824 of cornea 812.The flap or layer 818 is then placed back onto the cornea 812 andallowed to heal. Accordingly, ocular implant 630 can increase, decreaseor maintain the curvature of eye 810 as needed and/or desired as well asremove opaque portions of the eye.

Embodiment of FIGS. 60 and 61

Referring now to FIGS. 60 and 61, an ocular implant or material 930 inaccordance with the present invention is illustrated for treatment ofhyperopia or myopia. In particular, ocular implant or material 930 is adisk shape member, which is as thin as paper or thinner. Ocular implantor material 930 includes a center opening 932 for allowing intrastromalfluids to pass between either sides of ocular implant or material 930.Basically, ocular implant or material 930 is constructed of a suitabletransparent polymeric material utilizing diffractive technology, such asa Fresnel lens, which can be utilized to correct the focus of the lightpassing through the cornea by changing the refractive power of thecornea. Since ocular implant or material 930 is very thin, i.e., as thinas paper or thinner, the exterior surface of the cornea willsubstantially retain its original shape even after ocular implant ormaterial 930 is inserted into the cornea. Even if there is some changein the cornea, this change can be compensated by the refractive powersof the ocular implant or material 930.

Ocular implant or material 930 can be inserted into the cornea in any ofthe various ways disclosed in the preceding embodiments. In particular,ocular implant or material 930 can be inserted through a relativelysmall opening formed in the cornea by folding the ocular implant ormaterial 930 and then inserting it through the small opening and thenallowing it to expand into a pocket formed within the intrastromal areaof the cornea. Moreover, a thin layer or flap could be created forinstalling ocular implant or material 930 as discussed above.

The outer diameter of ocular implant or material 930 is preferably inthe range of about 3.0 mm to about 9.0 mm, while center opening 932 ispreferably about 1 mm to about 8.0 mm depending upon the type of visionto be corrected. In particular, ocular implant 930 can be utilized tocorrect hyperopia and/or myopia when using a relatively small centralopening 932 such as in the range of to about 1.0 mm to about 2.0 mm.However, if the opening is greater than about 2.0 mm, then the ocularimplant or material 930 is most likely designed to correct imperfectionsin the eye such as to correct stigmatisms. In the event of astigmatism,only certain areas of the ocular implant 930 will have a refractiveindex which is different from the intrastromal tissue of the cornea,while the remainder of ocular implant or material 930 has the samerefractive index as the intrastromal tissue of the cornea.

Preferably, ocular implant 930 is made from a biocompatible transparentmaterial which is resilient such that it can be folded and insertedthrough a small opening in the cornea and then allowed to expand back toits original shape when received within a pocket in the cornea. Examplesof suitable materials include, for example, substantially the same setof materials discussed above when referring to ocular implant ormaterial 430 or 630 discussed above.

While various advantageous embodiments have been chosen to illustratethe invention, it will be understood by those skilled in the art thatvarious changes and modifications can be made therein without departingfrom the scope of the invention as defined in the appended claims.

What is claimed is:
 1. A method of modifying a patient's live corneahaving a main optical axis and an exterior surface, comprising the stepsof forming an incision in the exterior surface of the live cornea,separating a flap from the front of the live cornea forming first andsecond opposed internal surfaces via the incision, the first internalsurface facing in a posterior direction of the live cornea and thesecond internal surface facing in an anterior direction of the livecornea, removing three-dimensional portions of intrastromal tissue fromat least one of the first and second surfaces of the cornea to form aninternal ring-shaped pocket which surrounds the main optical axis of thecornea, introducing a resilient, ring-shaped ocular implant into thepocket of the live cornea between the first and second surfaces, andcompletely encapsulating the ocular implant between the first and secondinternal surfaces to retain the ocular implant between the first andsecond internal surfaces and to modify the cornea overlying the ocularimplant.
 2. The method according to claim 1, wherein the forming,separating, introducing and encapsulating steps are performed withoutfreezing the cornea.
 3. The method according to claim 1, furthercomprising directing a laser beam onto at least one of the first andsecond internal surfaces in a predetermined pattern to incrementally andsequentially ablate the three-dimensional portions of the cornea to formthe pocket.
 4. The method according to claim 1, wherein the ocularimplant is sized and positioned between the first and second surfaces toreduce the curvature of the cornea.
 5. The method according to claim 1,wherein the ocular implant is sized and positioned between the first andsecond surfaces to increase the curvature of the cornea.
 6. The methodaccording to claim 1, wherein the ocular implant is sized and positionedbetween the first and second surfaces to maintain the cornea's originalcurvature.
 7. The method according to claim 1, wherein the introducingstep includes introducing a hydraulic polymer ocular implant.
 8. Themethod according to claim 1, wherein the incision is locatedsubstantially at the periphery of the cornea and extendscircumferentially about the main optical axis of the cornea.
 9. Themethod according to claim 1, wherein the separating and removing stepsfurther comprises the step of leaving intact intrastromal tissueextending between the first and second internal surfaces.
 10. The methodaccording to claim 9, wherein the intact intrastromal tissue is locatedsubstantially at the center of the cornea such that the ocular implantsurrounds the intact intrastromal tissue.
 11. The method according toclaim 1, wherein the introducing step includes introducing a transparentpolymeric ocular implant.
 12. The method according to claim 11, whereinthe ocular implant is a corrective lens with at least a portion of theocular implant having a refractive index different from that of thecornea.
 13. The method according to claim 12, wherein the correctivelens has a substantially uniform cross-section.
 14. The method accordingto claim 13, wherein the corrective lens has a uniform refractive index.